Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

UVa scientists detail salmonella protein

26.09.2003


A protein in Salmonella bacteria called SipA invades healthy human cells by using two arms in a "stapling" action, according to scientists at the University of Virginia Health System. The U.Va. researchers, working with colleagues at Rockefeller University in New York, report their findings in the September 26 edition of the magazine Science.


Edward Egelman, professor of biochemistry and molecular genetics at U.Va., said the significance of this research is that it could be possible to design molecules to prevent SipA from binding to a protein called actin, preventing the severe infection associated with Salmonella.

According to the Centers for Disease Control and Prevention, various types of the Salmonella bacteria are responsible for up to four million infections and 500 deaths in the United States every year. Salmonella can cause diarrhea, fever and abdominal cramps. Most people recover without treatment, but young children, the elderly and people with compromised immune systems are at risk for developing severe infections. There is no vaccine to prevent Salmonella-related sickness.

Egelman and his colleagues found that SipA works as a molecular "staple" and tethers itself to actin, a protein found in all human cells. SipA can polymerize actin into long filaments.



This activity may explain how this bacterial protein helps rearrange a cell’s cytoskeleton, or the inner scaffold that gives a cell shape and provides motility. By remodeling the cytoskeleton of host cells, bacterial proteins such as SipA allow the Salmonella bacteria to infect these cells.

"This is a cunning evolutionary pathway that has developed with Salmonella," Egelman said. "It has the interesting property of being able to control the host actin filaments by using arms to do it. It has actually evolved, we believe, to mimic human proteins that bind to actin. This allows Salmonella to become a Trojan horse of sorts, causing healthy cells to engulf the Salmonella bacteria."

Research teams at U.Va. and Rockefeller University used an electron microscope, x-ray crystallography and 3-D reconstruction to image the SipA protein. They found that the molecule is unexpectedly compact, heart shaped, with a globular core, flexible polypeptide extensions and a large patch that may help SipA bind to the mostly acidic surface of actin.

Bob Beard | EurekAlert!
Further information:
http://hsc.virginia.edu/news
http://www.sciencemag.org

More articles from Life Sciences:

nachricht A Map of the Cell’s Power Station
18.08.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau

nachricht On the way to developing a new active ingredient against chronic infections
18.08.2017 | Deutsches Zentrum für Infektionsforschung

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

A Map of the Cell’s Power Station

18.08.2017 | Life Sciences

Engineering team images tiny quasicrystals as they form

18.08.2017 | Physics and Astronomy

Researchers printed graphene-like materials with inkjet

18.08.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>